Bat survey conducted to protect species

By Logan Ranger District of the Uinta-Wasatch-Cache National Forest

Note: The Logan Cave is closed to the public in order to protect the bats.

The Uinta-Wasatch-Cache National Forest and Utah Division of Wildlife Resources are conducting an annual survey of the Townsend’s big-eared bat population in Logan Cave. The goal of the agencies is to maintain a healthy population of the species, which is the primary bat species that occupies the cave.

Logan Cave has been closed to the public via a permanent gate since 1996 to protect the bats and the cave itself. The gate was unfortunately deemed necessary after a posted sign failed to enforce a voluntary closure implemented during the winter of 1993/1994.

The cave’s condition, along with its population of Townsend’s big-eared bats, had severely declined over years of mistreatment and disturbances by some visitors. A 1977 independent article in the Deseret News reported that the cave was filled with trash, damaged stalactites and stalagmites, and graffiti on the walls. Forest Service bat surveyors working in the cave documented that bats had been shot and also described a strong urine smell, evidence of many fires, and large amounts of trash.

The Townsend’s big-eared bats use Logan Cave for winter hibernation and as a maternity colony to raise their young. They are known to be extremely sensitive to disturbances at their roosting sites, which explains why surveyors found only 19 of them in the cave in the winter of 1995/1996, during the final stage of the voluntary closure order. But since the 1996 installation of the gate, the bats have rebounded. Surveys conducted the next year (winter 1996/1997) found an average of 32, and an average number of 241 were observed during the winter of 2008/2009. The most recent survey conducted on February 1 of this year reported 385.

Strong measures were necessary to protect Logan Cave’s population of Townsend’s big-eared bats, but they have successfully helped their numbers increase. However more work remains to be done, both locally and nationally, in order to ensure the survival of the species. Although their range covers much of western North America, their overall population remains in sharp decline.